Type-wheel construction for printing telegraph receivers



R. D. SALMOIIN April 3, 1951 TYPEWHEEL CONSTRUCTION FOR PRINTING TELEGRAPH RECEIVERS 2 Sheets-Sheet 1 Filed Aug. 19, 1947 Inventor Allorney April 3, 1951 R. D. SALMON 2,547,046

TYPEWHEEL CONSTRUCTION FOR PRINTING TELEGRAPH RECEIVERS Filed Aug. 19, 1947 2 Sheets-Sheet 2 :lllorney Patented Apr. 3, 1951 TYFE-VVHEEL CONSTRUCTION FOR PRINT- ENG TELEGRAPH RECEEVERS Reginald Dennis Salmon, Croydon, England, as-

signor to Creed and CompanyLimited, Croydon, England Application August 19, 1947, Serial No. 769,429 In Great Britain May 24, 1946 13 Claims. 1

This invention relates to printing telegraph receivers.

The principal object of the present invention is to provide an improved construction of type wheel, specially suitable for high speed operation in a printing telegraph receiver.

Type wheels have been constructed in which separate spring controlled type bars are mounted so as to be movedcy a printing hammer parallel to the axis of a rotary carrier. Such constructions are however not suitable for page printing receivers, since it is difficult therewith to arrange for visible printing, i. e. for'the character just printed to be visible.

For this latter purpose it ha been proposed to mount a typewheel for rotation and for vertical movement on a spindle mounted in a carriage traversable parallel to a horizontal printing platen. The typewheel comprised individual type pallets slidable radially of the wheel at right angles .to the axis thereof to effect printing. The typewheel was normally located below the line of printingand was raised into printing position and moved'out of such position for each printing operation.

An object of the present invention is to reduce the diameter, and hence the moment of inertia of a typewheel for a page printing telegraph re ceiver as compared with previously known corstructions. To this end the typewheel is, according to the present invention, constructed with pivoted type bars, lying substantially parallel to the axis of the typewheel. It will he noted that type pallets that are slidable are necessarily of sufficient length to ensure bearing surfaces to guide them in a straight line movement, and that the diameter of the typewheel is reduced by the present type bar construction.

According to the present invention, therefore, there is provided a page printing telegraph receiver comprising a platen, a carriage, means for causing relative movement between said platen and said carriage for character spacing, a typewheel mounted on said carriage, type bars pivoted on said typewheel and lying substantially parallel to the axis thereof, a type face on each type bar and means for moving a selected type bar so that the type face thereon moves substantially ing the carriage, for moving the typewheel into and out of printing position and for effecting printing, whilst Fig. 2 shows a vertical cross section of the typew-heel.

Referring to the drawings, the typewheel coinprises a sleeve 1 within which are fixed selflubricating bearings 2 and 3. These bearings slide on a vertical shaft 4 fixed in a carriage t. The sleeve l is thus free to rotate about shaft 4 and to move vertically on said shaft. The typewheel carries individual type bars 8, of which one only is shown at 6. The lower end of each type bar fits into a slot in a disc l. This disc I and other discs presently to be described are held so as to rotate with sleeve l by a keyway 8 on that sleeve and are separated vertically by means of distance pieces 9, on the sleeve Each type bar is shaped as shown, so as to pivot on the outer edge of a disc l6 and is held in a slot in an upper disc H by an individual spring. This spring consists of a piece of piano wire l2 one end of which is hooked round the type bar at 53. The wire passes through an outer slot in the disc l and is bent into a coil at it. The other end of the wire l2 passes through an inner slot in disc 7 and is retained behind a flanged piece 55 fixed to the underside of disc H3. Fixed to the upper end of the type bar are two type faces l6 carrying the lower and upper case characters respectively.

The typewheel is shown in Fig. l in a position to effect printing of the upper case character It but is normally in such a position shown in Fig. 2 that both type faces are below the line of printing so as to leave visible the last character printed. The means for raising or lowering the typewheel will be described hereinafter.

A selected type bar is struck by a printing hammer ll in a manner hereinafter described and during this printing movement, the type bar moves in its slot in the disc H. This movement is lubricated by means of a felt pad l3 saturated with oil, and held on the upper surface of disc H by a flange 59 on the upper end of sleeve i. The rear edge of each type bar '6 abuts against this felt pad it when the type bar is in normal position.

The typewheel is rotated by means of a gear wheel 28 fixed to the sleeve 5 and meshing with an idler gear 2| rotatably mounted in. the car riage 5. The gear wheel 20 is provided with twenty seven. teeth, the spaces between which correspond in position to the type bars 5 so that the gear wheel 20 can also function as a cor a rector wheel for the position of the typewheel, as will be explained. The idler gear 2! has fewer teeth than the gear wheel 2! so as to reduce its diameter and thus its moment of inertia. The idler gear 21 is of such depth that the gear wheel 28 is in mesh therewith both in the normal position of gear wheel 20 and in either of the positions to which it is lifted for printing to take place.

Fixed to the idler gear 2! is a bevelgear 22, which is in mesh with a bevel gear 23 fixed to a sleeve 26 rotatably mounted in a bearing on the carriage and coaxial with a spline shaft 25. The sleeve 2G can move along the spline shaft 25 and is driven threefrom through a self-aligning coupling in the manner described in U. S. Patent No. 2,382,668 in order selectively to position the typewheel;

The carriage 5 is supported for horizontal movement along guide rails 26 and 21 so that it can be moved parallel to a platen 28 the position of which is indicated in broken lines. The carriage 5 is supported and guided along guide rail 2? by means of two sets of rollers. One of these sets is visible in the drawing and consists of four rollers, three of which 3! can be seen. These rollers are 90 apart in a bracket member 32. This bracket member is fixed on one end of a frame member 33, forming part of the carriage 5, to the other end of which is fixed a similar bracket member carrying a similar set of rollers also bearing on guide rail 27.

The carriage 5 is traversed for character spacing parallel to the platen 28 and along the guide rails 26 and 2'! and the spline shaft 25 against a spring 34 by means of pawls 35, 36 which ongage racks 37, 38 in the manner described in my co-pending application bearing No. 766,551, filed August 6, 1947. now Patent No. 2,524,854, dated October 10, 1950. When the carriage 5 is released for return to the beginning of a line, it is drawn back to that position by spring 3 3, its return being cushioned by abutment of the carriage 5 against one end of a lever 39 pivoted at 40 in the framework of the machine. The other end of lever 39 actuates the plunger il of a dashpot 42.

The typewheel is raised into printing position and lowered out of printing position by means of a bail .43 actuated by a cam 44 through levers 4-5 in the manner described in my said co-pending application, and controlled by a member 4%, also in the manner described in that application, so that either the upper type face I6 or the lower type face of type bar 6 is brought into printing position. The ball l3 is engaged by rollers 4'6 on one end of a lever 43 pivoted at 49 on the carriage 5. The other end of lever 48 carries a pin 59 to which is fixed a trunnion resting between gear wheel 29 and a diSc 5i. During the full extent of the typewheel movement the teeth of gear wheel 23 are in engagement with the teeth of the idler gear 2i as previously pointed out.

To effect printing, a printing ball 52 is operated by a printing cam 53. The printing ball 52 is engaged by rollers 5 on a lever 55 pivoted at 55 on the carriage 5. A lever 5'! is pivoted at 55 on lever 55 and is constrained to follow lever 55 by means of a spring 59 connecting the two levers. The head 60 of the printing hammer is fixed to an inverted U-link 6i pivoted at 62 to the lever 51 and is guided for movement radially of the type wheel by a slot 33 fitting around the reduced end 64 of the vertical shaft 6. The

4 striking face of the head 60 is shaped so as to be parallel with the type faces it when these strike the sheet supported on the platen 28.

A lever 65 is pivoted on the carriage 5 at 65 and is connected with lever 55 by spring 61. Thus when ball 52 is moved clockwise to effect printing, lever 65 is moved clockwise about its pivot 66 by spring 57 and a corrector tooth 68 fixed to the end of lever 65 enters between the teeth of gear wheel 20. Fixed to corrector tooth 68 is a notched plate 69 and one of the notches therein embraces gear wheel 28 to hold the type wheel steady against vertical movement, while corrector tooth 68 holds it against rotary movement. If the typewheel has been raised to print from the upper-type face l6, having thereon a lower case character, the lower of the two notches in toothed plate 59 embraces gear wheel 23 and the head 60 of the printing hammer strikes behind the upper type face. If the typewheel is raised to print from the lower of the two type faces it, having thereon an upper case character, the upper of the two notches in toothed plate 69 embraces gear wheel 28 and the head 60 of the printing hammer strikes behind the lower type face it.

Iclaim:

l. Page printing telegraph receiver comprising a platen, a carriage, means for causing relative movement between said platen and said carriage for character spacing, a shaft mounted on said carriage, a typewheel comprising a sleeve movably and rotatably mounted about said shaft, means for rotating said typewheel, a plurality of type bars pivoted around the periphery of said sleeve, said type bars lying substantially parallel and close to the axis of said sleeve, a plurality of coiled springs having tangential ends, each of said springs cooperating with a different one of said type bars, one end of each .of said springs bein in engagement with that surface of said type bars which is distant from the axis of said sleeve, said springs positioned normally to urge said type bars radially toward the axis of said sleeve, means to retain the other end of each of said springs close to the axis of said sleeve, a type face on each of said type bars and m ans for moving a selected type bar so that the type face thereon moves substantially at right angles to the axis of said sleeve to effect printing.

2. Page printing telegraph receiver as claimed in claim 1, wherein said spring retaining means comprises a disc having a flanged axial portion, said disc axially mounted over said sleeve, said springs retained between the flanged portion of said disc and said sleeve, and said type bars pivoted on the peripheral edge of said disc.

3. Page printin telegraph receiver as claimed in claim 1, wherein said typewheel further comprises a slotted disc axially mounted over said sleeve, each of the slots in said disc extending radially through a portion of said disc from the periphery toward the axis thereof, each of said type bars arranged to movably rest in a different one of the slots in said disc, and to be guided thereby in a straight line toward said platen when selectively moved by said moving means.

4. Page printing telegraph receiver as claimed in claim 3 comprising means for lubricating the portions of said type bars moving in said slots.

5. Page printing telegraph receiver as claimed in claim 4 wherein said lubricating means coinprises a circular pad of fibrous material adapted to be impregnated with oil, said pad of smaller diameter than said slotted disc, and abutting against each. of said type bars when in normal position.

6. Page printing telegraph receiver comprising a platen, a carriage, means for causing relative movement between said platen and said carriage for character spacing, a shaft mounted on said carriage, a typewheel comprising a sleeve movably and rotatably mounted about said shaft, means for rotating said typewheel, said means comprising a gear wheel fixed to said sleeve, and an idler wheel rotatably mounted on said carriage and meshing with said gear wheel, driving means mounted in the fixed portion of said receiver, means for coupling said driving means with said idler wheel, said typewheel comprising a plurality of type bars pivoted around the periphery of said sleeve, said type bars lying sub- .stantially parallel close to the axis of said sleeve, a plurality of coiled springs having tangential ends, each of said springs cooperating with a different one of said type bars, one end of each of said springs being in engagement with that surface of said type bars which is distant from the axis of said sleeve, said springs posi tioned normally to urge said type bars radially towards the axis of said sleeve, means to retain the other end of each of said springs close to the axis of said sleeve, a type face on each of said type bars and means for moving a selected type bar so that the type face thereon moves substantially at right angles to the axis of said sleeve to effect printing.

7. Page printing telegraph receiver as claimed in claim 6 in which said gear wheel is provided with spaces between the teeth thereof corresponding in position with the type faces on said typebars, said receiver further comprising a corrector tooth and means operative upon each printing action to place said corrector tooth in one of the spaces between the teeth of said gear wheel to hold said typewheel against rotation during printing.

8. Page printing telegraph receiver comprising a platen, a carriage, means for causing relative movement between said platen and said carriage for character spacing, a shaft mounted on said carriage, a typewheel comprising a sleeve movably and rotatably mounted about said shaft, means for rotating said typewheel comprising a gear wheel fixed to said sleeve, an idler wheel rotatably mounted on said carriage and meshing with said gear wheel, said gear wheel having spaces between the teeth thereof, a, corrector tooth engageable in one of said spaces to hold the typewheel against rotation during printing, means for raising said typewheel into printing position for a printing operation, means associated with said corrector tooth to hold said gear wheel against vertical movement whilst printing is effected, said typewheel comprising a plurality of type bars pivoted around the periphery of said sleeve, said type bars lying substantially parallel and close to the axis of said sleeve, a plurality of coiled springs having tangential ends, each of said springs cooperating with a diiferent one of said type bars, one end of each of said springs in engagement with that surface of said type bars which is distant from the axis of said sleeve, said springs positioned normally to urge said type bars radially toward the axis of said sleeve, means to retain the other end of each of said s rings close to the axis of said sleeve, a type face on each of said type bars, means for moving a selected type bar so that the type face thereon moves substantially at right angles to the axis of said sleeve, driving means mounted in the fixed portion of said receiver, and means for coupling said driving means with said idler wheel.

9. Page printing telegraph receiver as claimed in claim 8 in which said typewheel is normally located out of the line of printing and is raised into the printing position for a printing operation and in which said idler wheel is of such depth as to mesh with said gear wheel in any of the positions of the typewheel.

10. Page printing telegraph receiver as claimed in claim 8 in which said idler wheel is provided with fewer teeth than said gear wheel.

11. Page printing telegraph receiver as claimed in claim 8 in which each type bar carries two type faces corresponding to upper and lower case characters respectively and means is provided for raising the typewheel to bring a selected row of type faces into the printing line.

12. Page printing telegraph receiver as claimed in claim 8 further comprisin a printing bail, a rotating cam member driven in response to received signals, a first lever pivotally mounted on said printing carriage, said lever slidably mounted in contact with said bail and adapted to be operated thereby, a second lever pivotally mounted on said first lever, spring means disposed between said levers, whereby said levers are normally urged together, a printing hammer pivotally connected to said second lever at an end thereof distant from the pivot mounting adjoining said first and second levers, said hammer adapted to selectively strike said type bars to effect printing, and means to actuate said bail according to the rotations of said cam member.

13. Page printing telegraph receiver as claimed in claim 12 comprising a corrector lever pivoted on said carriage and carrying said corrector tooth, and a spring connection between said first lever and said corrector lever to cause said corrector teeth to be pressed into contact with said gear wheel upon operation of said printing bail.

REGINALD DENNIS SALMON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 460,901 Way Oct. 6, 1891 2,382,668 Salmon Aug. 14, 1945 2,411,723 I-Iausman Nov. 26, 1946 

